purplehaze

So the past few days when I drive my truck The tach will sometimes bounce around until i let off and it idles then it will work and stay perfect still. Then I go to give is gas again and it works then all of a sudden bounces around then works. But just yesterday it seemed it was idling a little more i guess choppy than normal then seemed to run better later on after it was shut off. I put a code reader on it and got p0336 which is crank sensor A circuit range/performance. Also got p1690 which is a guess a communication error with the ECM and crank sensor I think. So should I just replace my crank sensor? Is there anything special you have to do other than remove the starter? cause i can see it its right behind it. thanks for any advice